This application claims priority to Korean Patent Application No. 2003-28599, filed on May 6, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a method and system for a disc drive, and more particularly, to a method and system for detecting a state of the disc drive, that is master (MA) or slave (SL), even without a jumper.
2. Description of the Related Art
A disc drive 100, such as a CD-ROM drive, a DVD-ROM drive, or a hard disc drive, includes setting pins 102 indicating a master (MA), a slave (SL), or a cable select (CSEL) state. FIG. 1 is a back view of a disc drive showing a connector pin of the disc drive.
As shown in FIG. 1, the disc drive 100 generally includes an audio output terminal 101, MA/SL/CSEL setting pins 102, an interface terminal 103, and a power source input terminal 104.
The audio output terminal 101 is connected to an audio signal input terminal of a sound card, and the MA/SL/CSEL setting pins 102 are used for setting the disc drive 100 in one of the MA, the SL, or the CSEL state. The interface terminal 103 is typically formed of 40 pins and is used for transmitting control signals and data between the disc drive 100 and a host (not shown). Although it is not shown, a pin 28 of the interface terminal 103 is internally connected to a pin 46 of the MA/SL/CSEL setting pins 102. The power source input terminal 104 is formed of two grounding pins, a 5V power supply pin, and a 12V power supply pin.
FIG. 2 is a magnified drawing of a setting pin to set a disc drive in one of a master (MA), a slave (SL), and a cable select (CSEL) state, and FIG. 3 is a detection circuit diagram of a disc drive according to prior art.
As shown in FIG. 2, in a case where a jumper 102-1 is linked to MA pins 41 and 42 among the MA/SL/CSEL setting pins 102 in instance (a) of FIGS. 2 and 3, the pins 41 and 42 in FIG. 3 are in a low (or grounded) state. In this case, a low signal is output to a micom (not shown) in a host, and the disc drive 100 is detected as a MA drive.
In addition, in a case where the jumper 102-1 is linked to SL pins 43 and 44 among the MA/SL/CSEL setting pins 102 in instance (b) of FIGS. 2 and 3, the SL pins 43 and 44 in FIG. 3 are in a high state (+Vcc). In this case, a high signal is output to the micom (not shown) in the host, and the disc drive 100 is detected as a SL drive.
Furthermore, in a case where the jumper 102-1 is linked to CSEL pins 45 and 46 among the MA/SL/CSEL setting pins 102 in instance (c) of FIGS. 2 and 3, the CSEL pins 45 and 46 in FIG. 3 are in one of the high and low states according to a CSEL signal input from a pin 28 of the interface terminal 103. In this case, one of high and low signals is output to the micom (not shown) in the host, and the disc drive 100 is detected as one of the MA and SL drive.
In communications between the disc drive 100 and the host, the state of the disc drive 100, whether it is in the MA or SL state, is decided according to the place where the jumper 102-1 is linked. However, if the jumper 102-1 is improperly linked due to a user's mistake or the jumper is lost, it is impossible or almost impossible to detect the state of the disc drive 100. Namely, the jumper 102-1 is an essential element in this situation.
In FIG. 3, resistance R32 is added so that the disc drive 100 may be detected without the jumper 102-1. However, if the resistance R32 is shorted, an error occurs when detecting the state of the disc drive 100, especially when detecting the state of two disc drives. That is, when two disc drives are linked to the CSEL pin, one of the MA and SL drive can be detected; however when the two disc drives are not linked via the jumper, an error occurs when checking the state of the disc drives.
An example application for the above method of detecting the disc drive is disclosed in U.S. Pat. No. 5,796,684.
Thus, a mechanism is desired for reliably detecting the state of the disc drive even when the jumper is not present because a user fails to set the jumper or when the jumper is missing.